1. Field of the Invention
This invention relates to a new method and apparatus for installing sections of underground piping, and more specifically, to a new method and apparatus for installing sections of piping, horizontally underground, without 10 excavation, and without pre-drilling the tunnel in which the piping is to be installed.
2. Description of Related Art
Laying underground piping, whether it is laid horizontally or vertically, has been accomplished for many decades, in a variety of ways. The most obvious method, for laying piping underground, is to first excavate the site in which the piping is to be laid, then laying the piping, and then filling in that portion of the excavation that is not occupied by the piping. When piping is being laid vertically, there is only a small amount of wasted effort and expense, by first excavating, and then laying the piping. There is also only a small amount of unnecessary surface area destruction. The reason, is that if the piping is laid vertically, to open at the surface, as for example in an oil well, it is the intention, that the initial digging, that opens the surface, to the descended depth of the hole, is to remain as an opening, from the surface to said depth. The piping is then usually inserted, to keep the walls of the vertical hole from collapsing. It is rarely, if ever, the intention, when laying vertical piping, to lay the piping, and then permanently seal the surface opening.
However, when piping is to be said horizontally, to run substantially parallel with the surface, at a certain depth beneath the surface, then the excavation, must of necessity, dig up much more of the ground than will remain open, and the destruction of the surface is the destruction of something that must be restored after the piping is laid. Therefore, the first obvious disadvantage, to excavating the site of the laying of horizontal piping, is that a large amount of effort and expense is expended, to dig a large hole, that must be filled in again, as soon as the piping is in place. The second obvious disadvantage, is that if the site under which the piping must be placed, is man-finished, such as by a paved surface, then the expensive paved surface, that is initially torn up and destroyed, to allow the site to be excavated, must be replaced after the piping has been laid, and the excavation filled in. An expensive paved surface has therefore been lost, and another one has to be paid for to take its place, after the piping was laid.
Devices have been invented, to dig horizontally underground, between two pits, that flank the surface area, that is to be horizontally tunneled under. Some of those devices operate rotationally, and others operate by being pushed or pulled through the earth. Some of those devices can be used over long distances, others can only be used between site flanking pits that are relatively close together. However, after any of the digging devices have been used, whether they are rotational horizontal drilling devices, or push-pull horizontal drilling device, it is then necessary to install the piping. The pipe installation operations, using the known devices, are therefore two stage operations. The first stage involves digging the horizontal tunnel, and the second stage involves inserting the piping into the horizontal tunnel. An obvious problem of continuous concern, is that there is always the possibility that the tunnel will collapse before the piping has been inserted, or during the piping insertion stage, or that the insertion of the piping will cause parts of the horizontal tunnel to collapse.
An object of the present invention, is to provide a method and apparatus, for installing horizontally running underground piping, without first having to excavate the site under which the piping is to be installed.
A second object of the present invention, is to provide a method and apparatus, for installing horizontally running underground piping, that will substantially reduce, or eliminate, the possibility of the piping tunnel collapsing, before the piping has been installed.
A third object of the present invention, is to provide a method and apparatus, for installing horizontally running underground piping, as part of the tunnel digging process itself.
A fourth object of the present invention, is to provide a method and apparatus, for installing horizontally running underground piping, that digs the piping tunnel, and installs the piping, in the same stage.